1. Field of Invention
This invention pertains to drives which transduce information to and from magnetic tape, and particularly to drives which accommodate tape-containing cartridges.
2. Related Art and Other Considerations
For decades magnetic tape has served as a medium for recording and storage of information. More recently, for such purposes magnetic tape has been housed in cartridges or cassettes. To perform recording and reading operations with respect to the tape, the cartridge is inserted into a device variously names as a tape drive, tape recorder, or tape deck. Examples of a cartridge-utilizing tape drives are the 8200 and 8500 family of helical scan recorders produced by Exabyte Corporation.
Typically a tape drive includes a frame wherein are housed various components and subsystems. For a helical scan recorder, for example, such components include cartridge loading/ejecting apparatus, apparatus for extracting tape from the cartridge into a tape path; and, a rotating drum proximate the tape path. The drum has one or more heads which transduce information relative to the tape.
Some drives tend to experience a phenomena known as over ejection. Over ejection occurs when the drive's loading/ejecting apparatus too vigorously or forcefully discharges a cartridge from the drive. Over ejection results in the ejected cartridge travelling too far out of the drive, perhaps with the cartridge even being launched totally out of the drive.
One particular cartridge, a 4 mm cartridge, is fashioned with a physical feature for mitigating the over ejection phenomena. Such 4 mm cartridge has a small circular depression or detente on a surface thereof which is engaged by a spring-like member internal to the drive slot. Engagement of the cartridge depression by the drive's spring-like member serves to lessen over ejection potential. Other standard tape cartridges, such as an 8 mm tape cartridge, do not have over ejection-combating physical features.
Over ejection is particularly problematic when a drive is incorporated into automated information handling systems such as a cartridge library. In a cartridge library, a cartridge transport device (sometimes referred to as a cartridge picker or gripper or end effector) removes an ejected cartridge from its nominal ejection position in a drive. In the nominal ejection position, the ejected cartridge extends partially from the drive slot by a predetermined protrusion distance. Cartridge transport devices assume that a cartridge to be extracted from a drive protrudes from the drive slot by the predetermined protrusion distance with only slight tolerance.
Consequently, over ejection foils a library's assumption regarding cartridge location, and can result in numerous problems including cartridge grip failure.
Tape drives typically have a drive frame, a front portion of which is commonly termed a bezel. The bezel has an elongated, essentially rectangular slot through which the cartridge travels as the cartridge is inserted into and ejected from the drive. During cartridge insertion and ejection, a housing or case of the cartridge typically contacts or even scrapes a lower perimeter of the bezel's slot. Such contact tends to scrape off small particles of the cartridge case, resulting in dirt or debris. Such dust can dislodge and enter either the interior of the cartridge or the interior of the drive, and thereby contaminate the tape. Tape contamination, in turn, endangers tape transducing integrity.
What is needed, therefor, is apparatus for combating the over ejection problem of tape drives. Advantageously such apparatus should not contribute to dust generation or tape contamination.